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Query: UNIPROT:P04040 (Catalase)
 3,577 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An underinvestigated aspect of the mitogenic and cell regulatory actions of vanadium is the regulation of gene expression. Among the fifteen cellular genes studied in cultured mouse C127 cells, vanadium (as 10 microM sodium vanadate) increased levels of mRNA of the actin and c-Ha-ras to four times control values. These increases represented de novo synthesis of mRNA, since they were inhibited by actinomycin D. Vanadate did not increase mRNA corresponding to c-src, c-mos, c-myc, p53, HSP70, pODC or RB genes, and expression of c-erb A, c-erb B, c-sis and c-fes genes was undetectable whether vanadium was present or not. Expression of a third gene affected by vanadium, c-jun, was augmented by addition of a reductant or oxidant together with the vanadate. Addition of NADH (marginally effective on its own) or H2O2 (effective alone) dramatically enhanced the effect of vanadate on c-jun gene expression. Catalase inhibited the effect of NADH partly. The vanadate-stimulated expression of actin and c-Ha-ras mRNA were unaffected by oxidants, reductants, metal chelators, or anti-oxidant enzymes. Evidently vanadate acts by two separate mechanisms on these two categories of genes. The alternate hypothesis that the actions of vanadate on actin and c-Ha-ras were mediated by a protein kinase cascade was inconsistent with the following observations. Neither insulin nor epidermal growth factor increased mRNA levels of c-Ha-ras or actin gene. Neither genistein (a tyrosine kinase inhibitor) nor pretreatment with 12-O-tetradecanoylphorbol-13-acetate blocked the actions of vanadate on these genes. Clearly the biological actions of vanadium depend in part on altered expression of genes. Since two of the genes are proto-oncogenes, this mechanism is potentially relevant to the mitogenic responses of cells to vanadium.
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PMID:Vanadate-induced gene expression in mouse C127 cells: roles of oxygen derived active species. 143 69

We tested the preventive effects of catalase, an enzymatic scavenger of hydrogen peroxide, or dimethyl sulfoxide (DMSO), a hydroxyl radical scavenger, on intravenous alloxan-induced lung edema in four groups of pentobarbital sodium-anesthetized, ventilated dogs for 3 h: saline (20 ml.kg-1.h-1) infusion alone (n = 5), alloxan (75 mg/kg) + saline infusion (n = 5), catalase (150,000 U/kg) + alloxan + saline infusion (n = 5), or DMSO (4 mg/kg) + alloxan + saline infusion (n = 5). Catalase or DMSO significantly prevented the increase in plasma thromboxane B2 and 6-keto-prostaglandin F1 alpha over 3 h after alloxan and the accumulation of extravascular lung water after 3 h [3.95 +/- 0.52 (SE) g/g with catalase, 3.06 +/- 0.42 g/g with DMSO] but not early pulmonary arterial pressor response. An electron microscopic study indicated that catalase or DMSO significantly reduced the endothelial cellular damages after alloxan. These findings strongly suggest that hydrogen peroxide and hydroxyl radical are major mediators responsible for intravenous alloxan-induced edematous lung injury in anesthetized ventilated dogs.
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PMID:Pretreatment with catalase or dimethyl sulfoxide protects alloxan-induced acute lung edema in dogs. 144 76

Psoralens and other furocoumarins currently used in PUVA photochemotherapy are shown to have, to a variable extent, the ability to hasten the rate of ultraviolet-induced photooxidation of alpha-tocopherol (alpha-T) in ethanol or ethanol-phosphate buffer (pH 6.8). The sensitizing effect varies significantly with the substrate concentration and the nature of the furocoumarin used, and is dependent on the presence of oxygen. Scavengers of singlet oxygen, e.g., sodium azide, markedly inhibit the psoralen-sensitized photooxidation of alpha-T, whereas superoxide dismutase exerts an opposite, accelerating effect on the reaction rate. Catalase has no significant influence on the kinetics of alpha-T decay. Analysis of the products formed by psoralen-sensitized photooxidation of alpha-T in ethanol-phosphate buffer showed the presence of alpha-tocopherolquinone, its 2,3-epoxide and two related compounds containing the 7-oxaspiro[4.5]dec-1-ene-3,6-dione ring system. The nature of these products, coupled with the results of the kinetic experiments, suggest that psoralens induce a type II, oxygen-dependent photodegradation of alpha-T primarily mediated by singlet oxygen.
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PMID:Photodynamic degradation of vitamin E induced by psoralens. 161 Aug 86

Reactive oxygen metabolites have been postulated to play an important role in both toxic and ischemic forms of acute renal tubular epithelial injury. In the present study, we examined the effect of enzymatically generated hydrogen peroxide on LLC-PK1 cells, a renal proximal tubule cell line. Exposure of LLC-PK1 cells to glucose and glucose oxidase (GO; which generates hydrogen peroxide) resulted in cytotoxicity (as measured by trypan blue exclusion) which was dose dependent and increased linearly over time to 81 +/- 5% at 180 minutes (8 +/- 1% at time 0; mean +/- SEM, N = 3 to 7). Catalase (which decomposes hydrogen peroxide) completely prevented the cytotoxicity, confirming that the toxicity was due to hydrogen peroxide production. To assess whether the hydrogen peroxide toxicity was a direct effect or mediated by other toxic oxygen metabolites, several scavengers of reactive oxygen metabolites and iron chelators were used. Superoxide dismutase (a scavenger of superoxide) had no effect. Deferoxamine (DFO), an iron chelator, provided marked protection (GO alone 45.9 +/- 4.4%; GO + DFO 13.0 +/- 2.0%; control 7.1 +/- 1.2%; N = 15 to 17, P less than 0.001). Pretreatment with DFO (1 hr, then 2 washes to remove DFO before GO addition) also markedly inhibited the cytotoxicity, suggesting that DFO's effect was due to iron chelation. Two other metal chelators (dihydroxybenzoic acid and 1,10-phenanthroline) also significantly decreased the GO-induced cytotoxicity. However, three of four hydroxyl radical scavengers used (mannitol, dimethyl sulfoxide, sodium benzoate) did not significantly decrease cell death. Only dimethylthiourea provided protection.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Hydrogen peroxide cytotoxicity in LLC-PK1 cells: a role for iron. 166 14

Damage to the bases in DNA by the cupric ion-1,10-phenanthroline complex was investigated. Ten base products in DNA were identified and quantitated by the use of gas chromatography/mass spectrometry with selected-ion monitoring. DNA damage by the cupric ion-1,10-phenanthroline complex required the presence of a reducing agent such as ascorbic acid or mercaptoethanol. Products identified were typical hydroxyl radical induced products from the pyrimidines and purines in DNA, well-known from previous studies using various hydroxyl radical producing systems such as ionizing radiation, hypoxanthine/xanthine oxidase, or hydrogen peroxide in the presence of transition metal ions. Product formation was not significantly inhibited by typical scavengers of hydroxyl radical such as mannitol and sodium formate, but there was partial inhibition by dimethyl sulfoxide. Catalase substantially decreased formation of base products, and added hydrogen peroxide stimulated it, indicating the hydrogen peroxide dependency of DNA base damage. Superoxide dismutase afforded only a partial reduction in product yields in systems containing ascorbic acid. On the basis of the types of base products formed, the hydrogen peroxide dependency of product formation, and a previous report suggesting that DNA damage is due to a diffusible species [Williams, L. D., Thivierge, J., & Goldberg, I. H. (1988) Nucleic Acids Res. 16, 11607-11615], we propose that DNA base damage is caused by hydroxyl radical.
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PMID:Modification of bases in DNA by copper ion-1,10-phenanthroline complexes. 212 17

Reactivities of o-phenylphenol and its metabolites (2,5-dihydroxybiphenyl, 2-phenyl-1,4-benzoquinone) with DNA were investigated by a DNA sequencing technique, and the reaction mechanism was studied by UV-visible and ESR spectroscopies. In the presence of Cu(II), 2,5-dihydroxybiphenyl caused strong DNA damage even without piperidine treatment. Catalase, methionine, and methional inhibited the DNA damage completely, whereas mannitol, sodium formate, ethanol, tert-butyl alcohol, and superoxide dismutase did not. 2,5-Dihydroxybiphenyl plus Cu(II) frequently induced a piperidine-labile site at thymine and guanine residues. The addition of Fe(III), Mn(II), Co(II), Ni(II), Zn(II), Cd(II), or Pb(II) did not induce DNA damage with 2,5-dihydroxybiphenyl. When H2O2 was added, 2-phenyl-1,4-benzoquinone also induced DNA damage in the presence of Cu(II). Cu(II) accelerated the autoxidation of 2,5-dihydroxybiphenyl to quinone. An ESR study revealed that the semiquinone radical is an intermediate of the autoxidation. Catalase had no inhibitory effect on the acceleration by Cu(II). Superoxide dismutase promoted both the autoxidation of 2,5-dihydroxybiphenyl and the initial rate of semiquinone radical production. ESR spin trapping experiments showed that the addition of Fe(III) produced hydroxyl radical during the autoxidation of 2,5-dihydroxybiphenyl, whereas the addition of Cu(II) hardly did so. The results suggest that DNA damage by 2,5-dihydroxybiphenyl plus Cu(II) is due to active species other than hydroxyl free radical.
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PMID:DNA damage induced by metabolites of o-phenylphenol in the presence of copper(II) ion. 213 Sep 42

Catalase was purified to an electrophoretically homogeneous state from the facultative alkalophilic bacterium, Bacillus YN-2000, and some of its properties were studied. Its molecular weight was 282,000 and its molecule was composed of four identical subunits. The enzyme contained two protoheme molecules per tetramer. The enzyme showed an absorption spectrum of typical high-spin ferric heme with a peak at 406 nm in the oxidized form and peaks at 440, 559, and 592 nm in the reduced form. In contrast to the typical catalases, the enzyme was reduced with sodium dithionite, like peroxidases. The enzyme showed an appreciable peroxidase activity in addition to high catalase activity. The amino acid composition of Bacillus YN-2000 catalase was very similar to those of catalase from Neurospora crassa and peroxidase from Halobacterium halobium. The catalase content in the soluble fraction from the bacterium was higher with the cells grown at pH 10 than with the cells grown at lower pHs (pH 7-9).
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PMID:Purification and characterization of catalase from a facultative alkalophilic Bacillus. 214 54

Oxidation of glycated polylysine, a model compound of glycated protein, caused O2- production even at physiological pH, which could be accelerated by Fe3(+)-ADP. An enediol structure in glycated polylysine and related compounds, which could be confirmed by I2 uptake, was related to their oxidizability. Glycated polylysine was easily coordinated with Fe3+ even in the presence of phosphate at pH 7.4 and the formation of the iron complex was prevented by desferrioxamine. The exposure of unsaturated phospholipid liposomes to glycated polylysine-Fe3(+)-ADP system caused the production of a thiobarbituric acid-reacting substance, which was completely inhibited by 5 microM alpha-tocopherol or 150 microM desferrioxamine and slightly by 0.5 microM SOD. Catalase (20 micrograms/ml) and 10 mM sodium-benzoate did not affect the iron-glycated polylysine-induced lipid peroxidation, indicating no participation of an OH. in this reaction. A ferrous ion-coordinated glycated polylysine may act as an initiator of phospholipid peroxidation in the presence of oxygen. A possible mechanism of the iron-glycated polylysine-induced lipid peroxidation was discussed.
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PMID:O2- generation and lipid peroxidation during the oxidation of a glycated polypeptide, glycated polylysine, in the presence of iron-ADP. 215 61

Normal human neutrophils triggered by secretory IgA (sIgA) displayed low levels of cytotoxicity towards non-sensitized red blood cells. Catalase completely impaired this non-specific cytotoxicity (NSC), while superoxide dismutase (SOD) significantly enhanced it, suggesting a key role for hydrogen peroxide (H2O2) in the lysis of target cells. Three heme-enzyme inhibitors, sodium azide, sodium cyanide and 3-amino-1,2,4-triazole, did not decrease NSC, but significantly enhanced it, suggesting that the mechanism involved is not dependent upon myeloperoxidase (MPO). Heat-aggregated IgG (HA-IgG) synergize with sIgA in promoting NSC. It was also found that gamma interferon significantly enhanced neutrophil-mediated NSC induced by sIgA, its effect being more dramatic on NSC triggered by low concentrations of sIgA. The significance of these results is discussed.
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PMID:Neutrophil-mediated cytotoxicity induced by secretory IgA. 216 28

The effect of low concentrations of sodium oleate on the oxidation of oxymyoglobin to metmyoglobin has been examined. This long chain fatty acid results in a tripling of the initial rate (1.5-4.3 h-1) at which oxymyoglobin is converted to metmyoglobin and more than doubling of the rate of the long-term reaction (0.12-0.33 h-1). Examination of rate constant enhancement over a range of oleate concentrations (0-0.215 mM) has allowed an estimate of association constants for both phases of the reaction system. The peroxidase activity expressed by metmyoglobin towards hydrogen peroxide is inhibited by the presence of sodium oleate by a fivefold increase in the apparent Km value (0.33-1.77 mM). The observed changes in oxymyoglobin concentration over time are discussed in terms of competition between metmyoglobin, which acts as a peroxidase decreasing in situ concentrations of H2O2, and oxymyoglobin, which also is oxidized by the peroxide. It is shown that oleate can bind to metmyoglobin and azidometmyoglobin, but not oxymyoglobin. Catalase reduces the oxidation rates of oxymyoglobin in the presence or in the absence of oleate, substantiating the involvement of H2O2. The results are discussed in relation to the potential increase in tissue peroxidations in the presence of ischaemically elevated fatty acid concentrations.
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PMID:Free fatty acids enhance the oxidation of oxymyoglobin and inhibit the peroxidase activity of metmyoglobin. 217 98


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